The funcion of sensitivity is to producea response to a estimulus we receive

A estimulus is anything you see,hear,tuch,smell or tate.

They can be:Internal or external:

Internal stimuly came from inside our bodies like felling or thirst.

• External stimuly came fron outside our bodies,like the smell of a cake or the texture of a jumper.

The body as different receptors to recive different types of a stimuly.

• Internal receptors:recive the internal stimuli our bodies produce.They are all over aroun the bodie.They let us feel hunger or pain.

External receptorsrecive external stimuli.They are on the sensory organs. The eyes,the nose,the tongue,the ears and the skin.

The skin is the organ of touch.It is made up of three layers

A response is the body`s answers to a stimulus.

There are two tipes of responses,muscular and glandular.

Muscular respons are the movments our muscles make in responseto a stimulus.

Glandular responses occur when glands produce various substances in response to a stimulus.For example,your sweat glands produce sweat in response to heat.

RESPONSESRESPONSES

SIGHT The eye is the organ of sight.It is made up of the eyeball

and protected by the eyebrows,eyelids and

eyelashes.

1. Light goes through the cornea .

2. Ligth passes through the pupil the opening of the iris.

3. Ligth passesthrough the lenses which focuses the

image in the retina.4. The information in theretina

travels to the brain through optic nerve.

The nose is the organ of smell.The receptors of smell are in the pupitary

gland,inside the nostrils.

The ear is the organ of hearing.It has three parts:The outer ear,the middle ear and the

inner ear.

• The outer ear includes the ear and the ear canal.

• The middle ear incudes the eardrum and the small bones.

• The inner ear includes the cochlea and the auditory nerve

1. The outer ear recives sounds.

2. The middle ear changes sounds into vibrations.

3. The inner ear changes vibrations into nerve impulses that go tothe brain.

The tounge is the organ of tate.The receptors of taste are in the taste buds,all are around the tounge

The nervous system is made up of nerve centers and nervs.

•Nerve centers interpret the information and develop responses,forming the central nervous system.

•The central nervous system has two parts:

_ The brain is inside the skull. Is made up of the cerebrum,the cerebelum and the brain stem.

_The spinsal cord is made up of many neurons.Is protedted by vertebrae.

•The peripheral nervous system is made up of :

_Sensory nerves, which transmit information from the sensory and internal organs t the central nervous system

_Motor nerves,wihch transmit responses from the central nervous system to the muscles and glands.

Both the central and peripheral nervous system are made up of specialiced cells called neurons.

They are made up of a cell bodye,dendrites and axons.

Neurons recive information from other neurons through dendrites and transmit through the axons.

Is in charge of carrying muscular responses created by the nevous system

It is made up of the skeleton and the musculature

THE SKELETON

It is made up of all the bones in the body

•Head bones : skull bones and facial bones

•Trunk bones : spine and the rib cage.

•Linb bones : upper in the arms and lower in the legs.

Are located where two or more bones meet.

Bones are connected by resistant fibres called ligaments .

JOINTS

There are three types of joints

•Moveable joints : elbow

•Semi-moveable jointsn : vertebrae

•Fixed joints : the skull

Locomotor muscles are conected to the bones.When we contract or relax, they move the bones

HEAD MUSCLES:

•Masseter to chew food .

•Buccinator to open and close our lips.

•Orbicular to open and close our eyes.

TRUNK MUSCLES:

•Sternocleidomastoid yo move our head.

•Abdominal and pectoral to bent our trunk.

•Intercostal to move our ribs.

•Trapezius to connect our head and shoulders to our back.

•LIMB MUSCLES

•Biceps triceps and deltoid in the arm

•Quadriceps gluteous and calf muscles in the leg

Tendons are made of flexible and fibrous tissue.

They connect muscles to bones .

They cannot contact or relax like muscles.